Location of Folate Absorption
Only in the jejunum.
Location of Cobalamin/B12 Absorption
Only in the ileum.
Location of Mg2+ Absorption
Only in the ileum.
A protein that binds to and stores iron. It can be tested in a blood sample.
The gold standard for determining iron levels in a patient, however it is only assessed by staining bone marrow with Prussian Blue and is therefore almost never used. Ferritin gives a good estimate and is significantly less invasive.
Location of Iron Absorption
Mainly in the duodenum.
Competitors for Iron Absorption
Include lead, cobalt, strontium, manganese, and zinc. These will out-compete iron and lead to poisoning of the individual.
Facilitators of Iron Absoription
Ascorbate, citrate, amino acids, and iron deficiency will increase the amount of absorption.
Causes for Iron Deficiency
1. Decreased iron intake (vegetarians)
2. Decreased iron absorption (celiac disease, Crohn's disease etc.)
3. Increased iron loss (chronic bleeding)
4. Increased iron requirements (pregnancy / lactation)
How much daily blood loss does it take to become iron deficient?
Symptoms of Iron Deficiency
Koilonychia (spoon nails)
The best screening test for iron deficiency anemia (not as invasive as haemosiderin). Low ferritin says iron deficient, although ferritin results may appear high in an acute inflammation.
Treatment for Iron Deficiency
Oral iron. Start slow as to avoid constipation, nausea, and stomache cramps.
IM iron. Painful, but can deliver large doses.
IV iron. Needs to be done in hospital, takes many hours, and may cause serum sickness, fever, headache, or anaphylaxis.
Other Causes of Microcytic Anemia
Thalassemia (problems with hemoglobin production)
Lead poisoning (rare)
Over 50 and Anemic
You must rule out colorectal cancer before anything else.
Causes of Folate Deficiency
Can cause macrocytic and megaloblastic anemia.
Folate Deficiency Diagnosis
Order a serum folate test.
Order a red blood cell folate test.
Treatment of Folate Deficiency
Alcohol and Folate Absorption
Alcohol inhibits folate absorption.
B12 Storage Capacity
Your body stores enough B12 for years. This can be a problem with people going onto vegan diets as it will appear years later.
Homocysteine and Methylmalonic Acid Test
Confirmatory tests with borderline B12 test results.
Diagnosis of B12 Deficiency
Order a vitamin B12 serum test.